Double-chain-stitch sewing-machine.



. M. HEMLEB. DOUBLE CHAIN STITCH SEWING MACHINE.

APPLICATION FILED .lAN. 5|1910.

Patented May 25, 1915.

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WITNESSES.

ATTORNEY NITED STATES PATENT FICE.

MARTIN HEMLEB, OF ELIZABETH, NEW JERSEY, ASSIGNOR TO THE SINGER MANUFAC- TURIN G COMPANY, A CORPORATION OF NEW JERSEY.

DOUBLE-CHAIN-STITCH SEWING-MACHIN E.

Application filed January 6, 1910. Serial No. 536,748.

To all whom it may concern:

Be it known that I, MARTIN HEMLEB, a citizen of the United States, residing at Elizabeth, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Double-Chain- Stitch Sewing-Machines, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention has for its object to provide a simple and effective. lower-thread mechanism for machines for producing the double-thread v chain-stitch.

According to the present improvement in its preferred embodiment, the machine is constructed with a main-shaft longitudinally disposed beneath the work-plate and provided with a looper-actuating eccentric embraced by the strap of an eccentric rod pivotally connected with a rearwardly ex-.

tending arm of a rock-lever mounted upon a transverse fulcrum beneath the main-shaft carrier, whereby ai dwell is produced in the advance position of the looper.

Adjacent and in front of the main-shaft.

is disposed a pair of spaced thread-guiding arms having ahned thread-eyes between which moves a thrcad-eoiitrolling cam-disk;

fixed upon the mainshaft. The periphery of the thread-controlling cam is shaped for action in conjunction with the spaced threadguiding eyes to control the slack looperthread in conformity with thelooper movements. excepting in thedwell of the looper in its advance position in which it retains the needle-thread loop, at which time a projection upon the thread-control]iug cam-disk acts to pull off a supply oflooper-thread for a succeeding stitch.

In the accompanying drawingaFigure 1 is a perspective view. of a machine embodying the present improvement with certain.

Specification of Letters Patent.

Patented Ma 25, 1915.

parts-omitted, others in section, and still others indicated in dotted lines only. Fig. 2 1s a perspective view upon a larger scale represent ng a portion of the looper mechanism. Fig. 3 is a sectional elevation, lookmg forwardly, showing the thread-controlling device.

The machine is constructed with a frame of well known form, including the baseplate .1 from which rises the overhanging bracket-arm comprising the standard 2 and lateral member 3 terminating in the head 4. The base has in its forward portion the upwardly extending hearing I member 5 to which is applied in practice the, work-plate 6, shown in Fig. 1 in dottedlines only. J ournaled in the lower portion of the standard 2 and the bearing member-5 and be- 'I1eath the work-plate 6 is the rotary mainshaft 7 carrying the usual balance-wheel 8 and belt-wheel 9.

As indicated more fully in my Patent No.

924,903, of June 15, 1909, the needle-actuating rock-shaft mounted in the bracket-arm has operative connections with the mainshaft common to certain of the Singer machines, and is provided at its forward end with the crank-pin 10 embraced by one end of the link 11 whose other end embraces a lateral pin upon the collar 12 fixed upon the needle-bar 13 journaled in the head 4;

and carrying the needle-clamp 14c in which are shown secured by means of the clampscrew 15 the closely spaced needles 16.

Cooperating with both needles is an eyed looper whose blade 17 is disposed longitudinally of the machine and whose shank 18 is secured by means of the screw 19 in a transverse seat formed therefor in the looper-carrier 20 whose lateral hub 21 is formed at opposite ends with conical sockets fitted respectively to the similarly formed wheadQZ of the fulcrum-screw 23 and the embraced by the strap 28 at the upper end of the eccentric-rod .29 which is formed at its lower end. with a strap embracing the rearward end of a stud 30 secured by means of the nut 31 in an aperture in the rearwardly extending arm 32- of a rock-lever whose hub 33 is fulcrumed upon the pin 34 mounted in bearing lugs 35 and 36 of the bed-plate l beneath and transversely to the main-shaft 7. The forwardly projectmg arm 37 of the rock-lever carries. a stud 38 secured within an aperture therein by means of the clamp-nut 3-9 and having its proje'ctf' ing end embraced by a strap 40 at the rear- Ward end of the link 41 whose opposite end is provided with a similar strap 42 which is fitted to and embraces the ball 43 at one end of the stud 44 secured by means of the nut 45 in a transverse aperture of the loopercarrier 20 intermediate the hub 21 and its seat for the looper shank 18. The arts are so arranged that in the extreme upi er position of the actuating eccentric 27,substan'-' tially as represented in Fig. 1, the rock-lever arm 37 and its link connection 4l with the looper-carrier are approximately 1n ahnement, while in the other extreme POSltlOIl'Of the actuating eccentric the component members of the toggle device thus formed are in their elevated relative angular arrangement at which time the looper-blade is in its extreme retracted position.

The looper-supporting rock-shaft 26 has:

secured upon its rearward end by means of the set-screw 46 the .hub 47 of an upwardly extending forked arm 48 embracing the sideshift cam 49 fixed upon the main-shaft in a well known manner, by means of which vibratory movements are imparted to the fulcrum stud 23 in the plane of its axis and sidewlse needle-avoldmg movements are 1mparted tothe looper.

Fixed upon the main-shaft intermediate the looper-actuating eccentric 27 and the standard 2' are the thread-controlling v.camdisk 50 and the feed-actuating eccentric 51.

3 The irregular marginal portion of the camdisk 50 moves between the spaced threadguiding arms 52 formed with the foot-piece "53 adj ustably secured upon the bed by means of the fastening screw 54 and are provided with alined thread-guiding eyes 55 which are in practice separated by themargin of the disk 50 excepting at the indentation 56 therein, at which point-the looper-thread is permitted to pass freelyfrom one'to the other without appreciable deflection.

' The looper-actuating cam 27 and the thread-controlling disk 50 are fixed upon the main-shaft in such relation that the peripheral indentation 56 comes into register with the stationary thread-eyes 55 as the toggle members 37 and 41 approach their position of alinement and the' looper is about to assume its advanced position, immediately after which, and while the looper remains in advance position, a pull-ofi projection 57 of the disk 50 adjacent the recess or indentation passes between the guide-arms 52 and serves while the looper is stationary to deflect the looper-thread and pull off asupply of'the same through the tension device 58 for the succeeding stitch-foianing operation. The remainderofthe periphery of.

the thread-controlling disk 50 between the l pull-ofi portion 57 and the recess 56 is so shaped as to control the slack looper thread between the tension device and the looper to conform with the latters operative longitudinal loop-shedding and loop-seizing movements. i

In machines of this class as heretofore constructed, it has been. customary to impart a comparatively long throw to thelooper so that the drawing of a looper-thread supply for the succeeding stitch is effected by the advance movement "of the looper terminating during the upper-thread stitch-setting operation; but'the revision of ashort looperstroke followed hy a dwell in, the present construction necessitates other 'means of drawing of a supply of looper thread during the take-up action upon the needle-thread,

and this is done independently of the looper-- from the source ofsupply throughtheir're-g specive tension devices 60, thence through an adjustable thread-guide 61 upon the arm 3, through spaced guide-eyes 62 ofa fixed take-up arm 63 carried by the link 11, and through eyes 64in a thread finger 65 upon the needle-bar whence they are led downwardly past the thread-separating pin 66 upon the needle-clamp 14 to the needle-eyes. In descending, the needle-threads over the forward edge of the take-up arm 63 carries the thread-deflecting plate 67 whose shank V 68 is adjustably secured by, means of the fastening screw 69 upon the head 4 of the tion with the other needle-thread handling- 7 devices in controlling thethread.

The machine is shown provided with the usual feeding mechanism including the feeddog 7 O, and with the opposed pressenfoot 71 iecured' upon the lower: end of the presserin a well known manner and provided with a lifting 'leverf74 for raising the same.

Having thus set forth the nature of the invention, what 'I' claim herein is In 'a sewing machine, the combination with the frame and a work-plate mounted A bracket-arm, the plate 67 acting in conjuncr 72 pressed 'jinormally' downward by means of the spring 73 thereon, a rotary shaft, and a reciprocating needle operatively connected therewith, of a looper cooperating with said needle in seizing. needle-thread loops therefrom and presenting looper-thread loops thereto in the production of stitches, a carrier for said looper provided with a fixed stud, a fulcrum upon which said carrier is mounted to oscillate, a rock-shaft upon which said fulcrum is supported, actuating means for said rockshaft, 21 plural-armed rock-lever mounted 2. In a sewing machine, the combination with 'the frame and a work-plate mounted thereon, a rotary shaft, and a reciprocating needle operatively connected therewith, of a looper cooperating with said needle in the production of stitches, a carrier for said looper, a vibratory fulcrum for said carrier, means for imparting vibratory movements to said fulcrum, a plural-armed rock-lever mounted upon a fixed. fulcrum below the work-plate, a link connection intermediate an arm of said rock-lever and the loopercarrier, and a connection intermediate said shaft and another arm of said rock-lever whereby the rock-lever is vibrated to move the first-named arm of the rock-lever and its link connection with the looper-carrier into and out of alinementfor imparting operative loop-seizing and -shedding movements to the looper.

'8. In a sewing machine, the combination with the frame with the frame and a work-plate mounted thereon, a rotary shaft, and a reciprocating needle operatively connected therewith, of a looper cooperating with said needle in the production of stitches, a carrier for said looper, a fulcrum for said carrier disposed transversely to said shaft and movable in a plane embracing its own axis, a pluralarmed rock-lever mounted upon a fixed fulcrum below the Work-plate, a link connection intermediate an arm of said rock-lever and the looper-carrier, and a connection intermediate said shaft and another arm of said rock-lever whereby the rock-lever is vibrated to move the first-named arm of the rock-lever and its link connection with the looper-carrier into and out of alinement for imparting operative loop-seizing and -shedding movements to the looper.

4. In asewing machine, the combination rovided with a work-plate, a rotary shaft ournaled beneath the same, and a reciprocating needle operatively connected with said shaft, of a looper 006perating with said needle in the production of stitches, looper-actuating mechanism connected with said shaft independently of the needle-actuating mechanism and including means disposed wholly beneath the workpiate for imparting to the looper an advance operative movement followed bya dwell, and a looper-thread pull-01f comprising an operative thread-engaging member fixed upon and rotating with said shaft and timed to act during the dwell of the looper in drawing off a supply of looper-thread.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

H. A. KoRNEMANN, Jr., HENRY J. MILLER. 

